Aminative Functionalizations of 1,3-Dienes and Total Synthesis of Crokonoid A

The development of a three-component amidoazidation of 1,3-dienes serves as a basis for the first chapter of this thesis. An introduction will focus of some aminative transformations of alkenes and dienes and the intrinsic challenges set by allylic azides. Leveraging the photoredox activity of N-amidopyridinium salts, a mild access to 1,2-amidoazides from 1,3-dienes will be presented. While 1-aryl substituted 1,3-dienes were transformed exclusively to the 1,2-amidoazidation products, the 1-alkyl substituted counterparts undergo the same reaction to provide a mixture of 1,2- and 1,4-difunctionalized products. Taking advantage of the facile 1,3 shift of the allyl azides, known as the Winstein rearrangement, a dynamic kinetic reduction process was subsequently developed to enrich one of the two regioisomers. This chapter concludes with mechanistic investigations and a mechanistic proposal.

In continuation with the first chapter of this thesis, the second chapter deals with the development of a dual catalytic enantioselective three-component 1,2- amidocyanation reaction. A brief introduction on some photoinduced transition metal catalyzed and dual photoredox-transition-metal-catalyzed alkylative functionalization of 1,3-dienes will be presented, followed by our work on a new amidocyanation reaction of 1,3-dienes. After a brief scope, some mechanistic investigations and finally a mechanistic proposal will be presented.

The third chapter of this thesis focuses on our journey towards the total synthesis of crokonoid A, a highly rearranged diterpene. After a brief introduction on ent-kauranes, our retrosynthesis will be presented. The synthesis of this compound posed significant challenges due to the highly unstable nature of its core. This work presents the strategies developed to overcome these issues, ultimately leading to the successful isolation of the target molecule. Chapter IV will focus on experimental details of chapter I-III.